}
  }

  @LazyInit @RetainedWith @CheckForNull private transient BiMap<V, K> inverse;

  @Override
  public BiMap<V, K> inverse() {
    BiMap<V, K> result = inverse;
    return (result == null) ? inverse = new Inverse() : result;
  }

  private final class Inverse extends IteratorBasedAbstractMap<V, K>
      implements BiMap<V, K>, Serializable {
    BiMap<K, V> forward() {

      return oldValue;
    }
  }

  @LazyInit @RetainedWith @CheckForNull private transient BiMap<V, K> inverse;

  @Override
  public BiMap<V, K> inverse() {
    BiMap<V, K> result = inverse;
    return (result == null) ? inverse = new Inverse<K, V>(this) : result;
  }

  static class Inverse<K extends @Nullable Object, V extends @Nullable Object>
      extends AbstractMap<V, K> implements BiMap<V, K>, Serializable {

        ImmutableListMultimap.<String, Integer>of().inverse());
    assertEquals(ImmutableListMultimap.of(1, "one"), ImmutableListMultimap.of("one", 1).inverse());
    assertEquals(
        ImmutableListMultimap.of(1, "one", 2, "two"),
        ImmutableListMultimap.of("one", 1, "two", 2).inverse());
    assertEquals(
        ImmutableListMultimap.of("of", 'o', "of", 'f', "to", 't', "to", 'o').inverse(),

  }

  public void testInverseMinimizesWork() {
    ImmutableSetMultimap<String, Character> multimap =
        ImmutableSetMultimap.of("of", 'o', "of", 'f', "to", 't', "to", 'o');
    assertSame(multimap.inverse(), multimap.inverse());
    assertSame(multimap, multimap.inverse().inverse());
  }

  private static <K, V> void assertMultimapEquals(

   */
  @Override
  public ImmutableSetMultimap<V, K> inverse() {
    ImmutableSetMultimap<V, K> result = inverse;
    return (result == null) ? (inverse = invert()) : result;
  }

  private ImmutableSetMultimap<V, K> invert() {
    Builder<V, K> builder = builder();
    for (Entry<K, V> entry : entries()) {
      builder.put(entry.getValue(), entry.getKey());
    }

   */
  Collection<V> get(@ParametricNullness K key);

  /**
   * Returns a view collection of all <i>distinct</i> keys contained in this multimap. Note that the
   * key set contains a key if and only if this multimap maps that key to at least one value.
   *
   * <p>Changes to the returned set will update the underlying multimap, and vice versa. However,

      }
    }
    return current;
  }

  /**
   * Returns the unique least value of type {@code C} that is greater than {@code value}, or {@code
   * null} if none exists. Inverse operation to {@link #previous}.
   *
   * @param value any value of type {@code C}
   * @return the least value greater than {@code value}, or {@code null} if {@code value} is {@code
   *     maxValue()}
   */

  public ImmutableCollection<V> values() {
    if (cachedValues != null) {
      return cachedValues;
    }
    return cachedValues = createValues();
  }

  // cached so that this.multimapView().inverse() only computes inverse once
  private transient @Nullable ImmutableSetMultimap<K, V> multimapView;

  public ImmutableSetMultimap<K, V> asMultimap() {
    ImmutableSetMultimap<K, V> result = multimapView;

   * <i>adding</i> to the returned set is not possible.
   */
  @Override
  public Set<K> keySet() {
    return super.keySet();
  }

  /**
   * Returns a collection of all values in the multimap. Changes to the returned collection will
   * update the underlying multimap, and vice versa.
   *

  /*
   * We have some considerable complexity in these create methods because of
   * Builder.buildKeepingLast(). The same Builder might be called with buildKeepingLast() and then
   * buildOrThrow(), or vice versa. So in particular, if we modify alternatingKeysAndValues to
   * eliminate duplicate keys (for buildKeepingLast()) then we have to ensure that a later call to